Vehicles with a substantially box-like design typically comprise two side walls, a roof and a rear which closes the roof and the side walls towards the rear at an obtuse angle or substantially at right angles. The separation edge through the obtuse rear means that the aerodynamic properties are unfavorable; for this purpose, rear spoiler devices for improving these properties are known in the art.
US 2004/0119319 A1 discloses a vehicle having a rear spoiler device. The roof air-guiding elements extend the roof surface of the vehicle towards the rear and can be folded inwards. Lateral air-guiding elements are further provided, in order to extend the entire surface of the truck aerodynamically towards the rear. The adjustment device is fitted to the rear door so that it can pivot away in the retracted state with the rear door and releases the loading space. The fitting to the rear door produces a step between the vehicle structure and the front edge of the roof air-guiding elements.
In the folded-in state, however, there generally remains a bulky arrangement which projects backwards, e.g. due to the folding lines and the mechanical elements of the adjustment device. Furthermore, complete opening of the rear door through 270° to-towards the front for abutment against the side wall is also thereby prevented.
US 2007/0126261 A1 discloses a further rear spoiler device which is attached to the side walls of the vehicle and can be folded in the longitudinal direction of the vehicle; the rear spoiler device fills up the entire rear surface of the vehicle.
U.S. Pat. No. 4,682,808 B describes a rear spoiler device which is configured by a plurality of vertical and horizontal air-guiding elements which are attached to different locations of the rear region. A rear spoiler device having a roof air-guiding element is set out as the prior art, the device only being provided in an internal region and being fitted to the roof surface so that it extends backwards over the rear region; the laterally abutting surfaces are not covered by the roof air-guiding element. However, air-guiding elements of this kind are complex to mount on the roof or on the vehicle structure and do not generally allow easy opening of the rear door.
U.S. Pat. No. 7,537,270 B2 discloses a rear spoiler device having a roof air-guiding element and lateral air-guiding elements which may exhibit different formations and which are partially provided for assembly on the rear door.
A pivotable or adjustable arrangement of air-guiding elements is also further disclosed in DE 10 2009 014 860 A1, DE 20 2009 014 476 U1, DE 20 2009 014 510 U1, DE 20 2009 015 009 U1 and DE 102 286 58 A1, for example. The air-guiding elements in this case are often fitted in the hinge region, which means that specific hinge designs are required. Furthermore, the air-guiding elements that can be used are generally limited in terms of the length thereof, in particular when the rear door is intended to be pivoted forward through approximately 270°. The operation and adjustment of adjustment systems of this kind is frequently complex.